Start Date: Oct 01, 2013
End Date: Aug 31, 2014
Phase 1, year 1 (completed). Evaluate insecticidal efficacy of cold-temperature (< 50 F) “Horn” or “Vaporphos” phosphine (100% purity) and warm-temperature (< 70 F) “Ecofume” phosphine (98.2%, carbon dioxide to phosphine mixture), and index relative to methyl bromide and sulfuryl fluoride at laboratory and pilot scales. Couple with residue analysis. Phase 2, year 2 (completed). Engineer phosphine fumigations to be efficacious on the shortest timescale possible through the integration of physical (e.g., vacuum) and chemical approaches, such as developing fumigant mixtures with other gases. Graduate toward commercial scales and scenarios used by the walnut industry for fumigation; included ~5,000 specimens of the most phosphine-tolerant life stage of dried fruit beetle, navel orangeworm, codling moth, red flour beetle, and warehouse beetle. Phase 3, year 3 (current). Apply what is learned from Phase 1 & 2 and tailor to logistics of commercial walnut harvest and distribution. Disseminate results of this study through local and annual meetings of the California Dried Fruit and Nut Association.